1. Field of the Invention
The present invention relates to a water purifier for removing residual chlorine or the like contained, for example, in the city water and more particularly to the water purifier having a primary filter for removing residual chlorine and a secondary filter disposed downstream of the primary filter with the intention of extending the life of the purifier by preventing the secondary filter from being clogged.
2. Description of the Related Art
The city water generally contains, although the content is very small, some amount of residual chlorine which gives uncomfortable feeling such as odor. In some cases, therefore, the city water has been filtered through a filtering material such as activated carbon to remove the residual chlorine. However, there has been a fear that, if the residual chlorine is removed and if the water is left in a relatively pure state, microorganism such as bacteria, fungi, etc. may proliferate and flow out.
As a water purifier for preventing the microorganism from flowing out, there is an apparatus for example described in the Japanese Utility Model Laid-Open Publication No. 61-22594 wherein a secondary filter for removing the bacteria and consisting of a hollow fiber unit is disposed downstream of the primary filter having granular activated carbon. The problem of the outflow of microorganism described above can be avoided with the water purifier described above.
In the conventional water purifier provided with the primary and secondary filters as described above, however, there has been a disadvantage that microorganisms proliferate between both filters and the proliferated microorganisms clog the secondary filter to considerably shorten the filtering life of the water purifier. In order to eliminate this problem, there has been an example wherein activated carbon applied with silver chloride as the primary filter has been used to suppress the proliferation of microorganism. However, since the proliferation of microorganism between the primary and secondary filters has not been considered in the conventional construction, the filtering life cannot be extended to a large extent.